Do you treat asymptomatic pyuria?

Management of Asymptomatic Pyuria

Asymptomatic pyuria should not be treated with antimicrobial therapy, as it is not an indication for treatment according to current clinical guidelines. 1

Definition and Diagnosis

• Pyuria is defined as the presence of increased numbers of polymorphonuclear leukocytes in the urine and indicates an inflammatory response in the urinary tract 1
• Asymptomatic pyuria refers to pyuria without symptoms or signs referable to urinary infection 2
• Pyuria is typically defined as ≥10 white blood cells per mm³ in an "enhanced urinalysis" or ≥5 white blood cells per high-power field on a centrifuged urine specimen 2

Evidence-Based Recommendations

General Population

• Pyuria accompanying asymptomatic bacteriuria is not an indication for antimicrobial treatment (strong recommendation, moderate-quality evidence) 1
• The presence of pyuria without symptoms does not distinguish between asymptomatic bacteriuria and symptomatic urinary tract infection 2
• In healthy premenopausal women, pyuria is common (occurring in 78% of high-risk women on at least one day) but rarely associated with bacteriuria or symptoms 3

Specific Populations

• Screening for or treatment of asymptomatic bacteriuria with pyuria is not recommended for:
  • Premenopausal, nonpregnant women (strong recommendation, high-quality evidence) 1
  • Diabetic women (strong recommendation, high-quality evidence) 1
  • Older persons living in the community (strong recommendation, moderate-quality evidence) 1
  • Elderly, institutionalized subjects (strong recommendation, high-quality evidence) 1, 4
  • Persons with spinal cord injury (strong recommendation, moderate-quality evidence) 1
  • Catheterized patients while the catheter remains in place (strong recommendation, high-quality evidence) 1
  • Infants and children (strong recommendation, low-quality evidence) 1

Exceptions Where Treatment May Be Indicated

• Pregnant women should be screened for bacteriuria (not just pyuria) and treated if results are positive, regardless of the presence of pyuria 1
• Patients undergoing urologic procedures where mucosal bleeding is anticipated should be screened and treated for bacteriuria 1
• Before transurethral resection of the prostate, screening for and treatment of bacteriuria is recommended 1

Clinical Significance of Pyuria

• Pyuria is a hallmark of true urinary tract infection but has limited specificity when used alone 2
• The positive predictive value of pyuria for E. coli asymptomatic bacteriuria is only 4% in high-risk women 3
• Pyuria without bacteriuria may indicate non-infectious inflammation, tuberculosis, or other conditions 2

Potential Harms of Treatment

• Treating asymptomatic bacteriuria with pyuria leads to unnecessary antibiotic use 5
• Treatment may increase antimicrobial resistance 2, 5
• Several studies report that antimicrobial treatment of asymptomatic bacteriuria increases the short-term risk of pyelonephritis 5
• Treatment does not decrease the frequency of symptomatic infections 5

Common Pitfalls to Avoid

• Treating bacteriuria or pyuria based solely on laboratory findings without clinical symptoms 2
• Failing to recognize that pyuria without bacteriuria may indicate non-infectious conditions 2
• Assuming that the presence of pyuria always indicates infection requiring treatment 3
• Overtreatment of asymptomatic bacteriuria with pyuria, which contributes to antimicrobial resistance 6

Algorithm for Clinical Decision Making

1. Determine if patient has urinary symptoms (dysuria, frequency, urgency, suprapubic pain)

   • If symptomatic → Evaluate for UTI
   • If asymptomatic → Continue to step 2

2. Check if patient belongs to a special population:

   • Pregnant women → Screen and treat bacteriuria regardless of pyuria 1
   • Pre-urologic procedure with mucosal bleeding → Screen and treat bacteriuria 1
   • All other populations → Do not treat asymptomatic pyuria 1

3. If pyuria is discovered incidentally:

   • Without bacteriuria → No treatment, consider non-infectious causes 2
   • With bacteriuria but no symptoms → No treatment (except in special populations above) 1